Gimbal cannot keep camera upright

After a recent argument between my P2V+ and a wall, I was having some issues with the gimbal, Turns out that the impact had bent the gimbal arm slightly, causing the camera body to catch on the ribbon cable.

I've since stripped the gimbal and straightened the arm, then fitted a new ribbon cable. When I powered up the first time, the gimbal seemed to work as expected (although no video feed to the tablet). 10 minutes later, powered back on and now the gimbal seems to be struggling to keep the camera upright. The motors power up and the camera levels, the motors then appear to be "buzzing" for a second and the camera drops down. The motors pick it back up but then the buzzing starts and the camera drops again.

If I use the tilt wheel, I can angle the camera but the same thing happens, the motors will take the camer to its position, buzz and then drop the camera again. It's not a violent banging around type of affair that you see on youtube, it's a very subtle buzzing, before the camera drops.